1,2,5-thiadiazole polymers

ABSTRACT

Described and claimed are polymers containing 1,2,5-thiadiazole rings in the polymer chain and their preparations. The polymers are capable of being made into films, fibers, coatings and molded objects.

United States Patent MacDonald 1451 May 23, 1972 1,2,5-THIADIAZOLEPOLYNIERS Inventor: Robert Neal MacDonald, Wilmington, Del.

Assignee: E. I. du Pont de Nemours and Company,

Wilmington, Del.

Filed: Oct. 14, 1969 Appl. No.: 866,401

U.S. c1. ..260/78 R, 117 1 28.4, 117/161 P, 260/302, 260/306 R, 260/30.8R, 260/326 N, 260/33.4 R, 260/33.8 R, 260/47 c2, 260/47 (3,

260/47 ET, 260/75 H, 260/75 N, 260/75 5,

260/775 MA, 260/77.5 AQ, 260/78 s, 260/78 TF rm. c1 ..C08g 20/20 Field61 Search ..260/78, 302 D Primary ExaminerHaro1d D. AndersonAtt0rneyAnthony P. Mentis [57] ABSTRACT Described and claimed arepolymers containing 1,2,5- thiadiazole rings in the polymer chain andtheir preparations. The polymers are capable of being made into films,fibers, coatings and molded objects.

8 Claims, No Drawings chain are unknown, even though certain of theintermediates that could be used to make them are known compounds, e.g.,l,2,5-thiadia2ole-3,4-dicarboxylic acid, dicarbonyl chloride anddinitrile, and 3-hydroxy-l,2,5- thiadiazole-4-carboxylic acid [U.S. Pat.Nos. 2,990,409; 3,068,238; 3,117,972; Pesin et al., Zhumal ObshcheiKhimie, 32, 3505 (1962)].

Preferred polyhydrandes, polyoxadiazoles, polyethers and poly(amideurethanes). These preferred polymers can be represented by the generalformula 1,2,5-THIADIAZOLE POLYMERS BACKGROUND OF THE INVENTION 1. Fieldof the Invention This invention is concerned with polymers containing1,2,5- 5

thiadiazole rings in the polymer chain and the preparation of suchpolymers by condensation polymerization procedures.

2. Description of Prior Art Polymers containing 1,2,5-thiadiazole ringsin the polymer 0 the corresponding DESCRIPTION OF THE INVENTION Theinvention is defined broadly as a polymer containing 1,2,5-thiadiazolerings in the polymer chain. Such a polymer chain can be described ascontaining recurring divalent 1,2,5- thiadiazole-3,4-diyl groups,represented by the formula embodiments are polyesters, polyamides,

in which A represents the divalent l,2,5-thiadiazole-3,4-diyl group, nis the number of recurring units in the polymer chain and E is at leastone divalent radical selected from the group:

O O O c0; CORO-C in which R is alkylene oftwo to 20 carbons, phenyleneofthe formula a b f i wherein a, b, c, and d are hydrogen, alkyl, aryl,alkoxy, halogen, nitro or nitrile and wherein the two remaining bondseach attached to an oxygen in the polymer chain are ortho, meta or parato each other,

cyclohexylene of the formula wherein the ring is saturated and thesubstituents a, b, cand d'are hydrogen, alkyl, cycloalkyl, alkoxy orhalogen, and the two remaining bonds each attached to an oxygen in thepolymer chain are ortho, meta or para to each other,

aromatic group of the formula wherein J is oxygen, sulfur, alkylene ofone to 12 carbons, alkylidene, including polyhaloalkylidene, of two to13 carbons, and phenylene, and the rings may be substituted withhalogen,

group corresponding to the above aromatic group wherein one or both ofthe depicted aromatic rings is fully hydrogenated;

wherein R and R are hydrogen or lower alkyl and X is:

polymethylene of the formula -(CH,),, where n is an integer of 0-20,with the proviso that R and R may also be aryl when X is polymethylene,

phenylene of the formula R R o R R wherein R, R", R and R are hydrogen,alkyl, aryl, alkoxy, halogen, nitro or nitrile and the two remainingbonds each attached to a nitrogen in the polymer chain are ortho, metaor para to each other, with the proviso that R and R are hydrogen onlywhen X is phenylene, cyclohexylene of the formula wherein the ring issaturated, the R's are hydrogen, alkyl, cycloalkyl, alkoxy or halogenand the two remaining bonds each attached to a nitrogen in the polymerchain are ortho, meta or para to each other,

aromatic group of the formula wherein Y is oxygen, sulfur, alkylene ofone to l2 carbons,

alkylidenc, including polyhaloalkylidene, of two to at? carbons, andphenylene, and the rings may be substituted with halogen, and

group corresponding to the above aromatic group wherein one or both ofthe depicted aromatic rings is fully wherein T is o, m, or p phenyleneand R and R are as defined above;

wherein Q arylene or alk \'lar vlene of up to 12 carbon atoms;

wherein J is as previously defined above;

i ii iil The polymers of the invention are thermoplmtic solids which arereadily fabricated into thin coatings and molded objects, and may bemade as films or strong fibers by conventional solution spinning,solvent casting and/or melt spinning techniques. The films can be usedfor packaging purposes and the fibers can be employed in woven ornon-woven fabrics. The polymers are thermally stable, range fromrelatively low to relatively high in melting point, when higher meltinghave high glass transition temperatures, and are flame-resistant, i.e.,they are self-extinguishing after direct exposure to a flame. They areinsoluble in water, lower aliphatic alcohols, lower aliphatic ketonesand aliphatic hydrocarbons, but are variously soluble in phenols, e.g.,m-cresol, dimethylformamide, dimethylacetamide, hexamethylphosphoramide,N- methylpyrrolidone, 2,4dimethylsulfolane and polyhalogenated solventssuch as chloroform and hexafluoroisopropanol, and concentrated sulfuricacid.

The polymers are prepared by condensation polymerization from suitable3,4-difunctionally-substituted 1,2,5-thiadiazoles and difunctionalcoreactants such as glycols, diamines and diisocyanates. Mixed polymersmay be prepared using three or more direactive components as desired.

The known disubstituted 1,2,5-thiadiazoles that can be used directly informing polymers or indirectly through conversion to suitableintermediate derivatives are the 3,4-dicarboxylic acid, the3,4-dicarbonyl chloride, the dimethyl 3,4-dicarboxylate, the3,4-dicarbonitrile, the 3,4-dichloro derivative and the3-hydroxy-4-carboxylic acid.

SPECIFIC EMBODIMENTS OF THE INVENTION More detailed information onreaction conditions and alternatives is given in the following exampleswhich are illustrative and not limitative.

EXAMPLE 1 Preparation of a 1,2,5-thiadiazole polyester from a hydroxyacid via the acid chloride in situ HMPA hexamethylphosphoramide A. Amixture of 17.6 g. of 3-hydroxy-l,2,5-thiadiazole-4- carboxylic acid and260 ml. of thionyl chloride was refluxed under anhydrous conditions for3.5 hours. The resulting solution was first heated under distillingconditions at atmospheric pressure to remove most of the thionylchloride arid then at 98C./0.05 mm. for 2 hours to remove all volatileconstituents. A pale green transparent glassy product remained. This wastriturated with anhydrous ether to leave 8.2 g. of polymer as a whitepowder exhibiting a melting point of 283C. and an inherent viscosity of0.65 in dimethylacetamide at 25C.

Infrared spectra of this polyester show carbonyl, ester -c O-C, andconjugated unsaturation absorption corresponding to the polyesterstructure B. In a similar experiment 5 g. of 3-hydroxy-l,2,5-

thiadiazole-4-carboxylic acid, ml. of thionyl chloride, and 1.5 ml. ofhexamethylphosphoramide were stirred together under nitrogen for 1.5hours at ambient temperature, then refluxed for 3 hours. The system wasfiltered with a sintered glass Buchner funnel, and the white precipitatewas washed on the filter with pentane and vacuum oven-dried at 50C. togive 2.1 g. of l,2,5-thiadiazole polyester. The polymer exhibited aglass transition temperature of C., a melting point of 287C, and aninherent viscosity of 0.3 in hexamethylphosphoramide at 25C.

Anal. Calcd. for C O N,S:

C, 28.12; H, 0; N,2l.88;S, 25.00 Found: C, 28.01; H, 0; N, 21.62; S,24.9l.

EXAMPLE 2 Preparation of 1,2,5-thiadiazole polyester from a hydroxy acidvia the isolated acid chloride During the thermal polymerization at98C./0.05 mm. in example l, there was obtained 09 g. of white sublimatein the still head. This product was identified to be 3-hydroxy-l ,2,5-thiadiazole-4-carbonyl chloride, melting at lO5-l 18C. (resublimed m. p.l07.5l08C.

HOWC 0 Cl l I! ll bl diisoprop ylamine N s s Anal. Calcd. for C HO NSCl:

c. 21.88; H, 0.64;N, 17.03;Cl, 21.58 Found: C, 22.49; H, 0.76; N, 15.90;Cl, 21.40.

Infrared absorption shows OH, acid chloride carbonyl, and C =N.

A mixture of 0.1 g. (0.0006 mole) of the above3-hydroxyl,2,5-thiadiazole-4-carbonyl chloride and 2.5 ml. of 2,4-dimethylsulfolane was stirred at room temperature under nitrogen todissolve the acid chloride, and 0.1 ml. (0.0006 mole) of ethyldiisopropylamine was then added. After 27 hours stirring a whiteprecipitate which had formed was filtered, washed with water andacetone, and dried at 50C./l mm. overnight to give 0.01 g. of whitel,2,5-thiadiazole-3,4- polyester of inherent viscosity 1.08 indimethylacetamide at 25C.

EXAMPLE 3 Preparation of a 1,2,5-thiadiazole polyester from a glycol anda dicarboxylic ester CHzOC ,COCH3 HOCHsCHzOH In a 35 mm. X 8 inchpolymer tube were placed 8 g. (0.04 mole) of dimethyll,2,5-thiadiazole-3,4-dicarboxylate, 5.5 ml. (0.088 mole) of ethyleneglycol (freshly distilled from calcium hydride) and 0.013 g. oftetraisopropyl titanate. The mixture was heated under nitrogen 3.5 hoursat 180C. to distill off the methanol and form the glycol ester. With thetemperature maintained at 180C., the pressure was gradually reduced to1.1 mm. over an additional period of 40 minutes, after which thecontents of the tube was a brown viscous mass. Heating under vacuum wascontinued for an additional 40 minutes. The vacuum was released byslowly introducing nitrogen, and the tube was allowed to cool. The tubewas then broken to allow removal of the dark, hard plug of polymer. Thiswas dissolved in 30 ml. of hexafluoroisopropanol, and the dark viscoussolution was pressure filtered then stirred into 300 ml. of water. Avery light tan precipitate was formed. The solid was isolated on afilter, washed well with water and acetone, and dried in a vacuum ovenat 80C./5 mm. overnight to give 4.9 g. of poly( ethylenel,2,5-thiadiazole-3,4-dicarboxylate) melting at 193'C. and exhibiting aninherent viscosity of 0.2 in hexafluoroisopropanol at 25C.

Anal. Calcd. for C,H,O N,S:

C, 36.00; H, Found: C. 36.53; H,

2.00; N, H00; 5, l6.00 2.45; N, 13.99; S, l6.04.

wherein the substituents a, b, c and d may be variously hydrogen, alkyl,aryl, alkoxy (preferably methoxy), halogen, nitro or nitrile, and thehydroxyl groups may be positioned ortho, meta or para to each other;cyclohexylene diols corresponding to the formula wherein the ring issaturated and the substituents a, b, cand d may be hydrogen, alkyl,cycloalkyl, alkoxy or halogen and the hydroxyl groups may be positionedortho, meta or para to each other; aromatic diols of the formula whereinJ may be oxygen, sulfur, alkylene of one to l2 carbons, alkylidene,including polyhaloalkylidene, of two to 13 carbons, and phenylene, andthe rings may be substituted (especially with halogen); and diolscorresponding to the above aromatic diols wherein one or both of thedepicted aromatic rings may be fully hydrogenated.

EXAMPLE 4 Preparation of a polyester from an aromatic diol and 1,2,5-

thiadiazole-3 ,4-dicarbonyl chloride A solution of 5.275 g. (0.025 mole)of l,2,5-thiadiazole- 3,4-dicarbonyl chloride in 25 ml. of alcohol-free,anhydrous chloroform was added rapidly to a system composed of 1 L850 g.(0.025 mole) of l,l,l,3,3,3hexafluoro-2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 10 ml. (0.050 mole) of 5N aque ous sodiumhydroxide solution, 100 ml. of water, 0.5 g. of sodium lauryl sulfate(Duponol ME) and 25 ml. of alcoholfree chloroform being stirred rapidlyin an icewater-cooled, jacketed blender. Rapid stirring was continuedfor 5 minutes. The initial temperature was 6.5C. and the finaltemperature 28C. The system was poured into a large beaker and heated ona steam bath to remove chloroform and coagulate the polymer. Thecoagulum was washed with water four times in a blender and dried at80C./5 mm. overnight to give 12.2 g. of polyester exhibiting a glastransition temperature of 165C, a melting point of l972l3'C., and aninherent viscosity of 0. 12 in m-cresol at 25C.

Anal. Calcd. for C,,H CI F,O N,S: S, 5.23

Found: 5, 5.06.

infrared spectra of the polymer show carbonyl, ester C OC, unsaturatedCH and conjugated cyclic -C=C and C=N, corresponding to the polyesterstructure shown above.

The interfacial condensation process of this example can be varied withrespect to the solvent employed, the reaction temperature, theemulsifying agent and the acid acceptor. The organic solvent can be ahalocarbon (methylene chloride, carbon tetrachloride, dichloroethane,tetrachloroethane, etc.), an aliphatic or aromatic hydrocarbon (hexane,cyclohexane, toluene, etc.), an ether (diethyl ether, dioxane,tetrahydrofuran, etc.) or other inert solvent. The temperature can be inthe range 80C. to +100C., but is preferably about 040C. The

EXAMPLE Preparation of a 1,2,5 thiadiazole/straight-chain aliphaticpolyamide by interfacial condensation r M ii 1.

A solution of 10.550 g. (0.050 mole) of 1,2,5-thiadiazole-3,4-dicarbonyl chloride in 25 ml. of anhydrous, alcohol-free chloroformwas added rapidly to an ice-water-cooled, jacketed blender containing6.620 g. (0.0570 mole) of hexamethylenediamine, 140 ml. of water, 1 g.of sodium lauryl sulfate (Duponol ME), ml. (0.100 mole) of aqueous 5 Nsodium hydroxide and ml. of alcohol-free chloroform as the system wascooled and stirred rapidly at 9C. Stirring was discontinued after 5minutes, the thin emulsion was heated to remove the chloroform, and thepolymer was washed with water and dried at 50C./5 mm. to give 9.35 g. ofa thiadiazole polyamide. When heated in contact with a metal block thepolymer became adherent at 80C. and gave a smooth hard coating on theblock after being heated to 125C. and then cooled. 1t exhibited aninherent viscosity of 0.42 in m-cresol at 25 C.

Anal. Calcd. for C H O N S:

C, 47.25; H, 5.51; N, 22.04; S, 12.59

Found: C, 47.52; H, 6.18; N, 20.25; S, 12.38.

Infrared spectra of the polymer show NH, carbonyl, and saturated C-Hcorresponding to the polyamide structure shown above.

During the drying process at 50C. this low-melting polymer foamed togive on cooling a rigid foam in the shape of a ball the diameter of theevaporating dish.

The interfacial condensation procedure of this example can be variedlike that of example 4 with respect to alternatives of solvent, reactiontemperature, emulsifying agent and acid acceptor.

The polyamide formation described in this example is applicable to avariety of diamines. These include: polymethylene diamines of theformula RNI-KCH LNHR wherein R and R may be variously hydrogen, alkyl oraryl, and n is an integer of 020; phenylene diamines of the formulawherein the Rs may be variously hydrogen, alkyl, aryl, alkoxy(preferably methoxy), halogen, nitro or nitrile, and the amino groupsmay be positioned ortho, meta or para to each other; cyclohexylenediamines corresponding to the above phenylene diamines wherein the ringis saturated, the R's may be variously hydrogen, alkyl, cycloalkyl,alkoxy or halogen, and either or each amino group may also bear a singlelower alkyl substituent; aromatic diamines of the formula wherein Y maybe oxygen, sulfur, alkylene of one to 12 carbons, alkylidene, includingpolyhaloalkylidene, of two to 13 carbons, and phenylene, the rings maybe substituted (especially with halogen), and either or each amino groupmay also bear a single lower alkyl substituent; and diaminescorresponding to the above aromatic diamines wherein one or both of thedepicted aromatic rings may be fully hydrogenated. The properties of thenovel polymers that contain substituted phenylene rings will besubstantially the same the the properties of the polymers that containunsubstituted phenylene rings.

CH CH3 ClCO COC1+HI I(CHz)eI TH In the manner of example 5, a solutionof 10.550 g. (0.050 mole) of 1,2,5-thiadiazole-3,4-dicarbonyl chloridein 35 ml. of anhydrous, alcohol-free chloroform was added rapidly to anice-water-cooled, jacketed blender containing 8.240 g. (0.0570 mole) ofN,N'-dimethylhexamethylenediamine, 180 ml. of water, 20 m1. (0.100 mole)of aqueous 5N sodium hydroxide, 1 g. of sodium lauryl sulfate (DuponolME), and 25 ml. of alcohol-free chloroform as the system was stirredrapidly at 12C. Stirring was continued for 5 minutes, and the thinemulsion was heated to remove chloroform, washed and dried at 50C./5 mm.to give 9.7 g. of 1,2,5-thiadiazole polyamide. The polymer softened on ametal block at 74C. and gave a tough protective coating on the metalwhen heated to C. and cooled. It exhibited an inherent viscosity of 0.64in m-cresol at 25C.

Anal. Calcd. for c,,H,,o N,s=

c, 5107,11, 6.38; c, 51.30; H, 6.42;

Found: 1 1.20

EXAMPLE 7 Preparation of l,2,5-thiadiazolel-cycloaliphatic polyamide Asolution of 13.82 g. (0.0655 mole) of 1,2,5-thiadiazole- 3,4-dicarbonylchloride in 35 ml. of anhydrous, alcohol-free chloroform was addedrapidly to an ice-cooled, jacketed blender containing 6.62 g. (0.077mole) of piperazine, 187 ml. of water, 1.35 g. of sodium lauryl sulfate(Duponol ME), 26.2 ml. (0.131 moles) of aqueous N sodium hydroxide, and35 ml. of alcohol-free chloroform as the system was stirred rapidly at11C. After 5 minutes of stirring the thick white emulsion was treatedwith water and then heated on a steam bath to remove the chloroform andcoagulate the polymer. The coagulum was washed in a blender many timeswith water until the wash water was clear, washed once with acetone, andwas then dried at 80C./l mm. for 2 days to give 11 g. of white granularpolyamide. The polymer exhibited an inherent viscosity of 2.01 inm-cresol at 25C., a metal block stick temperature of 360C, and a glasstransition temperature of 2l2-214C. (The correspondingphthaloyl/piperazine polyamide has a glass transition temperature of 19ll94.5C.)

Anal. Calcd. for C,,H O N S:

C, 42.85; H, 3.57; N, 25.00; S, 14.28 Found: C, 42.79; H, 3.97; N,24.03; S, 14.09

Infrared spectra show amide carbonyl, saturated C-H, and conjugatedcyclic C N, corresponding to the 1,2,5- thiadiazole polyamide structureas indicated in the equation above.

A clear, tough film of the thiadiazole/piperazine polyamide was castfrom hexafluoroisopropanol and drawn 2X at l80200C. The film exhibited atensile/elongation/modulus of 4,480 psi/8.7%/l07,000 psi. This film didnot continue to burn when ignited in air, whereas a film of thecorresponding phthaloyl/piperazine polyamide supported combustion in airand was completely consumed. Films made of the polymers of this exampleare useful for packaging purposes.

EXAMPLE 8 A 1,2,S-thiadiazole/cycloaliphatic polyamide A. A solution of7.72 g. (0.0366 mole) of 1,2,5-thiadiazole- 3,4-dicarbonyl chloride in25 ml. of anhydrous alcohol-free chloroform was added rapidly to anice-cooled, jacketed blender containing 4.875 g. (0.043 mole) oftrans-2,5- dimethylpiperazine, 130 ml. of water, 0.75 g. of sodiumlauryl sulfate (Duponol ME), 14.64 ml. (0.0732 mole) of aqueous 5Nsodium hydroxide and 20 ml. of alcohol-free chloroform. After 5 minutesof rapid stirring the polymer was isolated as in example 7 with fourwater washes and one acetone wash to give 6.0 g. of granular polyamideexhibiting an inherent viscosity of 3.18 in m-cresol at C., an osmoticmolecular weight M 42,100 in chloroform at 25C., a stick temperature ona metal block of 305C, and a glass transition temperature of 233C. (Thecorresponding trans-2,5-dimethylpiperazine/phthaloyl polyamide exhibiteda glass transition temperature of 190C).

Anal. Calcd. for c,,,H,,o,N,s;

C, 47.64; H, 4.77; N, 22.22; S, 12.68. Found: C, 47.27; H, 4.88; N,21.88; S, 12.19.

Infrared spectra show amide carbonyl, saturated C-H, and conjugatedcyclic C N corresponding to the 1,2,5- thiadiazole polyamide above.

A tough, transparent film of the thiadiazole polyamide cast fromchloroform was drawn 2.5 at 230C. The film exhibited atensile/elongation/modulus of 17,700 psi/8.2%/268,200 psi. At roomtemperature an undrawn film showed a dielectric constant of 4.2, adielectric strength of 3.3 Kv/mil, and a dissipation factor of 0.008.

B. The polyamide of this example was also prepared by adding 0.642 g.(0.00304 mole) of 1,2,5-thiadiazole-3,4-dicarbonyl chloride in 15 ml. ofanhydrous, alcohol-free chloroform to 0.347 g. (0.00304 mole) oftrans-2,5-dimethylpiperazine and 0.842 ml. (0.00608 mole) oftriethylamine in 15 ml. of purified chloroform. The mixture was stirredfor 8 minutes and was then allowed to stand 6 days during which a totalof 3.6 ml. of triethylamine was added at three intervals. The polymerwas precipitated with hexane and was then washed once in a blender withacetone, 4 times with water, and again with acetone. The washed polymerwas vacuumoven dried overnight at C. to give 0.54 g. of snow whitegranular product. The polymer exhibited a stick temperature of 300C. ona metal block, and gave a viscous melt at 340C. from which filamentscould be drawn. 1t exhibited an inherent viscosity of 0.58 in m-cresolat 25C.

C. A solution of 21.10 g. (0.100 mole) of 1,2,5-thiadiazole-3,4-dicarbonyl chloride and 1.4 ml. (0.012 mole) of benzoyl chloride in70 ml. of alcohol-free, anhydrous chloroform was added rapidly to anice-cooled, jacketed blender containing 12.92 g. (0.113 mole) oftrans-2,S-dimethylpiperazine, 340 ml. of water, 8.00 g. (0.200 mole) ofsodium hydroxide and 60 m1. of alcohol-free, anhydrous chloroform. After5 minutes of rapid stirring, the polymer was isolated as in paragraph Aof this example. There was obtained 17 g. of colorless, granularpolyamide exhibiting an inherent viscosity of 1.63 in m-cresol at 25C.

A 12 percent by weight solution of this polymer in chloroform was dryspun into colorless fibers, which upon being drawn 2.5 over a pin at185C. and set in 40-60 lb. steam in an autoclave for 15 minutesexhibited a tensile strength of 1.83 g./denier, and elongation of 30percent, and an initial modulus of 30.7 g./denier. At 3 percentelongation its work recovery was percent and its tensile recovery was 98percent. The fibers are suitable for weaving into a fabric useful forapparel. A membrane made of the polymer of this example was fitted intoa cell into which salt water was pressured. Flow through the membranewas 12 gal/sq. ft./day and 78 percent of the salt in the original waterwas rejected, thus showing the utility of the polymer in waterdesalination.

Another utility is for coating wires. A solution of 40 grams of apolymer made according to example 8-C was dissolved in 180 ml. oftetrachloroethane. A length of no. 14 copper wirewas then drawn throughthe solution under a stationary bar held near the bottom of the solutionand then hung vertically to allow solvent to evaporate. The wire wasthen dipped again similarly for two more times and dried in an oven at100C. overnight. The clear, flexible tough coating on the wire served asan excellent insulation. A volt meter showed no current leakage throughthe insulating film at a potential of 1 10 volts.

EXAMPLE 9 Preparation of a l,2,5-thiadiazole/-m-phenylene polyamideC1CO- COC1 HzN NH2 Nai A solution of 1.277 g. (0.0118 mole) ofm-phenylenediamine in 40 ml. of anhydrous hexamethylphosphoramide wasstirred in an ice bath for 15 minutes, at which point 2.493 g. (0.0118mole) of 1,2,5-thiadiazole-3,4-dicarbonyl chloride solid was added.Stirring was continued at ice temperature for 2 hours, then at ambienttemperature for 3 days. The now-cloudy system was poured into 350 m1. ofwater to precipitate the polymer, which was then washed in a blenderwith water for four cycles and with ethyl alcohol for one cycle. It wasthen vacuum-oven dried at 80C. overnight to give 2.7 g. of polyamideexhibiting a glass transition temperature of 219C., a metal block sticktemperature of 255C., and an inherent viscosity of 0.12 in concentratedsulfuric acid at 25C. A bar, compression-molded at 265C./500 1b./1 min.,was shiny and hard, and showed considerable resistance to breaking. itcould be ignited in air but did not continue to burn when the flame wasremoved.

Infrared spectra of this polyamide show NH, secondary amide andconjugated unsaturation corresponding to the polyamide structure supra.

In another preparation by the above procedure a polyamide was obtainedexhibiting a glass transition temperature of 228C, a gradient bar sticktemperature of 293C, an inherent viscosity of 0.39.

EXAMPLE Preparation of a 1,2,5-thiadiazole/-p-phenylene polyamide1,2,5-thiadiazole-3,4-dicarbonyl chloride [10.55 g. (0.050 mole)] wasadded in three portions over a period of 16 minutes to a solution of5.40 g. (0.050 mole) of p-phenylenediarnine in 100 ml. of anhydroushexamethylphosphoramide as the latter was being stirred rapidly andcooled with an ice bath. The bath was allowed to warm gradually to roomtemperature, and stirring was continued until the precipitating polymerstalled the stirrer. After 20 hours the system was treated with water,and the polymer was washed in a blender three times with water and twotimes with ethyl alcohol. It was then dried at 80C./1 mm. for 3 days togive 11.0 g. of polyamide that did not stick to a metal block at 400C,and which had an inherent viscosity of 0.63 in concentrated sulfuricacid at C.

Anal. Calcd. for c d-1.19 0 8:

C, 48.78; H, Found: C, 47.96; H,

2.44; N, 22.76; S, 13.00. 2.50; N, 22.20; S, 12.55. 2.57 22.16

Infrared spectra of this polyamide show NH, carbonyl, and aromatic-typeunsaturation corresponding to the polyamide structure above.

EXAMPLE 1 1 Preparation ofa 1,2,5-thiadiazole/-aromatic polyamide 01COWCO 01 A thiadiazole/aromatic polyamide was prepared in the manner ofexample 10 by adding 11.550 g. (0.05474 mole) ofl,2,5-thiadiazo1e-3,4-dicarbony1 chloride at 1C. to a solution of 10.948g. (0.05474 mole) of 4,4'-oxydianiline in 100 ml. of purifiedhexamethylphophoramide. The polyamide obtained 17.2 g.) exhibited aglass transition temperature of 227C a gradient bar stick temperature of350C, a melt at 375C. from which flexible filaments could be drawn, andan inherent viscosity of 0.5 in m-cresol at 25C.

Anal. Calcd. for C,,,H ,O N,S:

C, 56.80; H, 2.96; N, 16.57; S, 9.47. Found: C, 55.42; H, 3.06; N,16.22; S, 9.21.

Infrared spectra show NH, carbonyl, cyclic conjugated C C and C N, andaromatic ether absorption corresponding to the thiadiazole polyamidestructure shown in the equation.

A 5 percent dimethylformamide solution of this polymer was spun intowater and flexible filaments were obtained. When hot-drawn 4X at 250C.over a pin the filaments were increased in strength.

A. To a solution of 10.620 g. (0.05474 mole) of isophthaloyl dihydrazidein 100 ml. of anhydrous hexamethylphosphoramide being stirred and cooledin an ice bath was added in 3 portions over a half-hour period 11.550 g.

Llama..-

(0.05474 mole) of 1,2,5-thiadiazole-3,4-dicarbonyl chloride,

and the system was stirred overnight. The polymer was precipitated intowater, washed in a blender four times with water and once with acetone,and dried at C./5 mrn. overnight. The resulting thiadiazolepolyhydrazide 15.0 g.) exhibited a glass transition temperature of 198C,a gradient bar stick temperature of 304C, a viscous melt at 325C. fromwhich filaments could be drawn, and an inherent viscosity of 0.16 inm-cresol at 25C.

Anal. Calcd. for C,,H,,O,N,,S:

C, 43.40; H, 2.41; N, 25.30; S, 9.57. Found: C, 41.14; H, 2.70; N,23.29; S, 10.14.

Infrared spectra show NH, carbonyl, and conjugated C C and C Ncorresponding to the structure shown above.

B. After-treatment of the polymer of part A.

l s in fi lil and increased unsaturation, corresponding to theoxadiazole structure shown in the equation immediately above.

it should be noted this second product obtained by thermal rearrangementof the first has a E segment in +A E-l-, termed arylenebis-[Z-(l,3,4oxadiazole)-5-yl], which has the formula EXAMPLE 13 Preparation of athiadiazole polyamide by means of a diisocyanate OCN NCO A thiadiazolepolyamide was prepared by heating 12.74 g. (0.0732 mole) oftoluene-2,4-diisocyanate and 12.74 g. (0.0732 mole) of1,2,5-thiadiazole-3,4-dicarboxylic acid in 60 ml. of anhydrousN-methylpyrrolidone for 19 hours at 100C. At this point carbon dioxideevolution had almost ceased, and a ml. sample of the reaction mixturewas precipitated by pouring it into methanol. The precipitate was washedand dried to give a thiadiazole polyamide exhibiting an inherentviscosity of 0.14 in m-cresol at 25C. and infrared absorptioncorresponding to NH, carbonyl, and conjugated C C and C= N. Theremainder of the reaction mixture was heated further at 150C. for anhour and at 110C. for 5 hours. It was then worked up in the same manneras the early sample to give 9 g. of thiadiazole polyamide with a glasstransition temperature of l91-197C., a gradient bar stick temperature of250C, an inherent viscosity of 0.1 l in m-cresol at 25C.

Anal. Calcd. for C,,H,O N S:

C, 50.80; H, 3.08; N, 21.53. Found: C, 50.96; H, 3.62; N, 19.86.

EXAMPLE 14 Preparation of a 1,2,5-thiadiazo1e poly( amideurethane) Asolution of 4.969 g. (0.0340 mole) of 3-hydroxy-1,2,5-thiadiazole-4-carboxylic acid and 5.915 g. (0.0340 mole) oftoluene-2,4-diisocyanate in 45 ml. of N-methylpyrrolidone was heatedunder nitrogen at 125C. for 25 hours, at which point carbon dioxideevolution had practically ceased. The dark solution was poured intomethanol, and the resulting precipitated was washed on the filterseveral times with methanol and dried at C./5 mm. overnight to give 3.1g. of poly(amide-urethane) exhibiting a glass transition temperature of174C., a gradient bar stick temperature of 273C, and an inherentviscosity of O. l 5 in m-cresol at 25C.

C, 47.85; H, 2.90; N, 20.28.

Found:

C, 52.93; H, 4.20; N, 19.20.

Infrared spectra show NH, carbonyl, and conjugated unsaturation.

EXAMPLE 1 5 Preparation of a 1,2,5-thiadiazole polyether [TF S/ 7 hstrongly adherent coating. The polymer exhibited a metal block sticktemperature of C.

Anal. Calcd. for C,-,H O,N S:

N, 9 O3. 3; N 8.

Found: 8:4

Infrared spectra of this polymer show ether, and conjugated cyclicC CandC N.

A portion of the original reaction mixture heated an additional 2 hoursat 150C. yielded polymer which exhibited an inherent viscosity of 0.14in m-cresol at 25C. and gave a negative copper oxide flame test forchlorine.

EXAMPLE 16 Preparation of a l,2,S-thiadiazolel-phenylene copolyamidewith dimethylpiperazine (DOOM-C001 l: HN I I A solution of 7.2 ml.(0.050 mole) of o-phthaloyl chloride and 10.55 g. (0.050 mole) of1,2,S-thiadiazole-3,4-dicarbonyl chloride in 50 ml. of anhydrousmethylene chloride was added rapidly to an ice-cooled, jacketed blendercontaining l2.92 g. O (0.1 l3 mole) of trans-2,5-dimethylpiperazine, 340ml. of

water, 8.00 g. (0.200 moles) of sodium hydroxide and 50 ml. of anhydrousmethylene Chloride- After 5 minutes of rapid 5 wherein Y is oxygen.sulfur, alkylene of one to l2 carbons,

Stirring the supernatant liquid was poured from the white alkylidene,including polyhaloalkylidene, 6r two 16 1.1 coagulate. This was washedin the blender with 500 ml. of carbons d phenylene' and the rings may beSubstitumd acetone and rinsed on a filter with 250 ml. of acetone. Thisi h h l and washing schedule was then carried out 5 times with water andgroup corresponding to the above aromatic group whercin a final timewith acetone. The snow white, granular copolya- 10 or b h f h depictedaromatic rings is fully mide was dried in a vacuum oven at 80C./5 mm.overnight. h d d; The weight of the polymer was 20.5 g. its inherentviscosity was 1.68 in m-cresol at 0.1 percent concentration at 25C., Rand it softened on a gradient bar at 335C. H I 15 iJ-N N-ild. forC 1-1 NAnal Calc H E, is iss; H, 6.56; N, 11.47. W

Calcd. for C H N.O,S:

c, 47.64; H, 4.77; N, 22.22; 5, 12.68 Found: wherein R and R" arehydrogen or lower alkyl;

c, 55.45; 11, 5.48; N, 16.78; s, 6.48

d 11 1 111 0 1 0 o In the process of this example man p-p thaloy c orideI can be used in place of or in combination with o-phthaloyl iN N( iTN 1chloride. By nitrogen and sulfur analysis this polymer cor- Pg respondsto a 1:1 thiadiazole/phenylene copolyamide with 12 R12dimethylpiperazine as indicated in the equation above.

A clear, colorless, viscous solution of the copolymer was whcrein T is0, m or p phenylene and 11 and 12 are as prepared by slowly rotating 0.5g. of polymer in 3 ml. of d fi d above; and chloroform from whichflexible, strong fibers could be readily dry spun. A film cast from thissolution was tough and clear. 0 0 0 0 1 claim iNHNH-iiZii NHNH-( i l. Afiber and film forming polymeric 1,2,5-thiadiazole consistingessentially of recurring units of the formula wherein Z is arylene ofsix carbon atoms or (CH where n is an integer of l to 20. 2. The polymerof claim I wherein E. of the recurring unit ---C--CE has the formula i iJ a o u 0 -iiN N where E is at least one divalent radical selected fromthe R12 group:

0 R R Q 3. The polymer of claim 2 wherein E of the recurring unit J LYhas the formula wherein R and R are hydrogen or lower alkyl and X is: 0CH3 0 polymethylene of the formula (CH where n is an in- 1| H g teger of0-20, with the proviso that R and R may also be N aryl when X ispolymethylene, phenylene of the formula CH3 R3 R4 4. The polymer ofclaim 1 wherein E of the recurring unit has the formula O 0 wherein R,R", R and R are hydrogen, alkyl, aryl, alkoxy, H g

halogen, nitro or nitrile and the two remaining bonds each attached to anitrogen in the polymer chain are ortho, meta or para to each other,with the proviso that R and R are hydrogen only when X is phenylene,

cyclohexylene of the formula 5. The polymer of claim 1 wherein E of therecurring unit has the formula wherein the ring is saturated, the Rs arehydrogen, alkyl, 0 O 0 cycloalkyl, alkoxy or halogen and the tworemaining L g P; L bonds each attached to a nitrogen in the polymerchain are ortho, meta or para to each other,

aromatic group of the formula l7 l8 6. The polymer of claim 1 wherein Eof the recurring unit 7. The polymer of claim I in the form of aself-supporting has the formula I film.

Ru Ru 8. The polymer ofclalm l m the form of a fiber.

mj wjg l0

2. The polymer of claim 1 wherein E of the recurring unit has theformula
 3. The polymer of claim 2 wherein E of the recurring unit hasthe formula
 4. The polymer of claim 1 wherein E of the recurring unithas the formula
 5. The polymer of claim 1 wherein E of the recurringunit has the formula
 6. The polymer of claim 1 wherein E of therecurring unit has the formula
 7. The polymer of claim 1 in the form ofa self-supporting film.
 8. The polymer of claim 1 in the form of afiber.